The object of the project is to measure levels of neutral hydrolases as a function of muscle innervation status in an attempt to assess the role of the nerve in control of the degradative phase of muscle protein and nucleic acid turnover. The enzyme systems under study are (a) soluble N-acetyl-L-phenylalanine ethyl esterase, (b) an insoluble phenylalanine releasing enzyme system, (c) a Ca ions-dependent protease, (d) RNase I, and (e) RNase II and its inhibitor. Projects include: (1) Further characterization of the enzymic components of the phenylalanine releasing system. (2) More detailed study of the time course of activity changes for neutral hydrolases as a function of skeletal muscle denervation including influence of the site of nerve section (proximal or distal), interplay of denervation and operation-generated generalized tissue trauma effects, sympathetic versus contractile motor unit denervation, and denervation of dystrophic muscle. (3) Survey of experimental muscle systems for Ca ion-dependent protease activity patterns. (4) Study of the influence of viral infection, interferon, and foreign RNA on mouse L-cell RNase II-inhibitor patterns.